How can I encourage mom to take meds/supplements? She has dementia; sometimes thinks I'm trying to "poison" her with the meds/supplements.

Mom was a teenager in the 1950s (poodle skirt and petticoat) and is still a rebel without a cause. Her homocysteine levels are high, of course but vitamin B and folate could help. Her primary doctor prescribed folate and her functional medicine doctor is recommending Vitamin Bs. Sometimes mom takes them and sometimes she says "no". What have you all tried to encourage our loved ones to take their meds/vitamins, etc.